| Acronym | Definition |
|---|
| IgA | Immunoglobulin A (antibody) |
| IgA | Intergovernmental Agreement |
| IgA | Independent Glass Association |
| IgA | Interactive Gambling Act (est. 2001) |
| IgA | International Glaucoma Association |
| IgA | International Geothermal Association |
| IgA | International Goat Association (Little Rock, Arkansas) |
| IgA | Indiana Golf Association |
| IgA | Income Generating Activity |
| IgA | Inagua, Bahamas (Airport Code) |
| IgA | Independent Grocers Alliance |
| IgA | Investigator's Global Assessment |
| IgA | Interested Government Agency |
| IgA | Intergranular Attack |
| IgA | Independent Grocers Association |
| IgA | Inside Global Address (computing) |
| IgA | Institute of Group Analysis |
| IgA | Inspector General Act of 1978 |
| IgA | In-Game Advertisement |
| IgA | Independent Grocers of Australia (Australia) |
| IgA | International Island Games Association |
| IgA | Inner Gimbal Angle (US NASA) |
| IgA | Idaho Golf Association |
| IgA | Interactive Genetic Algorithm (interactive evolutionary computation) |
| IgA | Illicit Gains Authority (legal entity, Egypt) |
| IgA | International Gay Association (now International Lesbian and Gay Association) |
| IgA | Integrated Graphics Array |
| IgA | Improved Gaussian Approximation |
| IgA | Illumina Genome Analyzer (genomics) |
| IgA | Indonesian Gas Association (Jakarta, Indonesia) |
| IgA | Instituto Guatemalteco Américano (Spanish: Guatemalan American Institute) |
| IgA | Institute for Gulf Affairs |
| IgA | International Governmental Agreement |
| IgA | Independent General Agent (insurance) |
| IgA | Integrating Gyro Accelerometer |
| IgA | Interleaver Growth Algorithm |
| IgA | Inhaled Gas Analyzer |
| IgA | International Graduate Achievement |
| IgA | Inhomogeneous Green's Function Approach |
| IgA | International Growers Association |